Does Opimax make a difference??

Peter, I'd agree with what you're saying about octane ratings. A car like the chevette was designed to run on four star leaded petrol and needs the timing backed off a couple of degrees to run happily on unleaded 95 RON. I hadn't done this but had experienced no problems except for a little detonation under load. I now use a lead additive for the valve seats, but a tank of optimax is higher octane and is what the engine is designed to use so any power increase(relative term in a chevette) is probably down to the timing again being right for the fuel rather than the wonder benefits of optimax. Apparently with a tank of optimax and the right additive it is possible to make up to 106 RON fuel - might give that a go! 

can you see them 'blockading' and creating the problem it did 5 years or so back?

brybusa wrote: The ZX ran a Hitachi(or however you spell it) turbo as standard...You been tweaking that as well?! yep, a good example is worth over 3K, the only true performance turbo'd bike of the 80's and I would well imagine the prices for a good one will keep rising. Early 2 strokes are in the 3-5K bracket now! rumours are at the mo that theres fuel blockades up and running, so no mater if its a 106RON chevette or Turbo'd ZX, we all better get SOME fuel tonight! Ill see you all at Tesco's!

my hitachi unit died after the 2 nd rebuild [impellers disintegrated]and finding another proved fairly dificult at the time ...the garret t3 will fit if you machine make a whole new conecting system [diffrent bores] and as so  many diffrent feeds  it becomes to bulky to have the ally valance on and so the belly pan has to stay off too ...but garrets are easy to come buy and about £!50 cheaper to rebuild  ..if i hadnt have been in the engineering trade  i wouldnt have bothered ...tooooo much hassle at the time .

are they going for that much????3k plus  ..you bang right the only 80 turbo bike to actually work ...it must have been a fad for the manufactures at the time  ..i mean why buy the 750 turbo .when you could have gone for the gpz 900 .that was on par for performance

were did you get the info on   the fuel strikes???

i carnt go to tescos    ..got caught doing a drive off  ..lol   only joking

I never used supermarket fuels and was running on Shell regular unleaded, which currently retails for around 84p per litre where I live. For some strange reason the Shell stations in my neck of the woods are around 4-5p a litre less than Esso, BP or Texaco, and the same price as supermarket fuels.

I live in North Wirral opposite Liverpool, and all the refineries are close by in Ellesmere Port. There have been 'stirrings' around the Stanlow refinery by protestors but nothing big has kicked off round here yet. I heard that there's now a greater demand for diesel due to the greater number of diesel cars in the UK, forcing diesel prices up a bit and upsetting farmers and the haulage industry-hence the present small protests.

I read somewhere that, as a product of the fractional distillation of crude oil, diesel accounts for 40% and petrol 60% of the distilled lighter fractions, and on the continent diesel cars account for around 40% of new car sales, although the lower fuel consumption of diesel engines would allow this proportion to rise a bit more before hitting saturation and causing demand for diesel to outstrip supply.

Oops, went off at a tangent there.... Anyway, I swapped over from Shell regular unleaded to Shell Optimax on my 1993 E34 540i and didn't notice any difference. I suspect that it may well prevent the build-up of deposits on the back of the inlet valves and in the ports etc but this would only really apply to new vehicles.

If you've got an oldish vehicle but still of modern technology, then it will probably have deposits already present from years of use on 'unclean' fuels. Having decoked engines in the past, it's hard to imagine a solvent in petrol removing baked on deposits that require much elbow grease to scrape off with a hard object-unless the oil companies know something I & BMW don't!

I think it may be wishful thinking to generalise about the effects and, judging from all the different experiences and responses on this subject so far, it looks like a case of one man's meat is another man's poison. It didn't work for me so I went back to the cheaper regular unleaded. I reckon I would have noticed a difference had I been running on supermarket fuel and then used Optimax, but I was already running on Shell regular.

So I guess, to sum up, if you tried it and it worked for you, then keep using it-if you can afford it!

 

pma1ums [/QUOTE wrote: my hitachi unit died after the 2 nd rebuild [impellers disintegrated]and finding another proved fairly dificult at the time ...the garret t3 will fit if you machine make a whole new conecting system [diffrent bores] and as so  many diffrent feeds  it becomes to bulky to have the ally valance on and so the belly pan has to stay off too ...but garrets are easy to come buy and about £!50 cheaper to rebuild  ..if i hadnt have been in the engineering trade  i wouldnt have bothered ...tooooo much hassle at the time . are they going for that much????3k plus  ..you bang right the only 80 turbo bike to actually work ...it must have been a fad for the manufactures at the time  ..i mean why buy the 750 turbo .when you could have gone for the gpz 900 .that was on par for performance were did you get the info on   the fuel strikes??? i carnt go to tescos    ..got caught doing a drive off  ..lol   only joking

my hitachi unit died after the 2 nd rebuild [impellers disintegrated]and finding another proved fairly dificult at the time ...the garret t3 will fit if you machine make a whole new conecting system [diffrent bores] and as so  many diffrent feeds  it becomes to bulky to have the ally valance on and so the belly pan has to stay off too ...but garrets are easy to come buy and about £!50 cheaper to rebuild  ..if i hadnt have been in the engineering trade  i wouldnt have bothered ...tooooo much hassle at the time .

are they going for that much????3k plus  ..you bang right the only 80 turbo bike to actually work ...it must have been a fad for the manufactures at the time  ..i mean why buy the 750 turbo .when you could have gone for the gpz 900 .that was on par for performance

were did you get the info on   the fuel strikes???

i carnt go to tescos    ..got caught doing a drive off  ..lol   only joking

[/QUOTE]

Info fuel strikes

http://forum.bmw5.co.uk/index.php?showtopic=4153

Thanks for the link re the veggie oil!

Off topic i know , when i had my GPz I was told that the turbo of the r5 GT Turbo was a straight replacement...never had it go to so I never found out..

Somewhere at home I have a video of the GPz turbo (small "z" = air cooled) and the GPZ900(capital Z water cooled) flying around a test track on their launch dates,,,thats gotta be worth sumat(?)

 

 

 

 

 

What is a Kwak Turbo!!

brybusa wrote: Ill try and dig the vid out and see if i can copy it...

thanks alot     much aprecitated if you could  ...i owe you one ..or if you need any fabrication /welding  doing ....no probs

peter

the kwak turbo    =====